Merge pull request #18 from FenrirWolf/time

ctr-std: add time module

ctr-std/src/lib.rs

@@ -16,6 +16,7 @@
 #![feature(int_error_internals)]
 #![feature(lang_items)]
 #![feature(macro_reexport)]
+#![feature(oom)]
 #![feature(optin_builtin_traits)]
 #![feature(prelude_import)]
 #![feature(raw)]
@@ -151,6 +152,7 @@ pub mod num;
 pub mod os;
 pub mod path;
 pub mod sync;
+pub mod time;
 
 // Platform-abstraction modules
 #[macro_use]

ctr-std/src/sys/unix/mod.rs

@@ -10,6 +10,9 @@
 
 #![allow(missing_docs, bad_style)]
 
+use io::{self, ErrorKind};
+use libc;
+
 pub mod ext;
 pub mod fast_thread_local;
 pub mod memchr;
@@ -18,9 +21,45 @@ pub mod os;
 pub mod os_str;
 pub mod path;
 pub mod thread_local;
+pub mod time;
 
-use io::ErrorKind;
+#[cfg(not(test))]
-use libc;
+pub fn init() {
+    use alloc::oom;
+
+    // By default, some platforms will send a *signal* when an EPIPE error
+    // would otherwise be delivered. This runtime doesn't install a SIGPIPE
+    // handler, causing it to kill the program, which isn't exactly what we
+    // want!
+    //
+    // Hence, we set SIGPIPE to ignore when the program starts up in order
+    // to prevent this problem.
+    unsafe {
+        reset_sigpipe();
+    }
+
+    oom::set_oom_handler(oom_handler);
+
+    // A nicer handler for out-of-memory situations than the default one. This
+    // one prints a message to stderr before aborting. It is critical that this
+    // code does not allocate any memory since we are in an OOM situation. Any
+    // errors are ignored while printing since there's nothing we can do about
+    // them and we are about to exit anyways.
+    fn oom_handler() -> ! {
+        use intrinsics;
+        let msg = "fatal runtime error: out of memory\n";
+        unsafe {
+            libc::write(libc::STDERR_FILENO,
+                        msg.as_ptr() as *const libc::c_void,
+                        msg.len());
+            intrinsics::abort();
+        }
+    }
+
+	// I don't think we have signal handling on the 3DS, so let's leave this
+	// blank for now
+    unsafe fn reset_sigpipe() {}
+}
 
 pub fn decode_error_kind(errno: i32) -> ErrorKind {
     match errno as libc::c_int {
@@ -48,6 +87,41 @@ pub fn decode_error_kind(errno: i32) -> ErrorKind {
     }
 }
 
+#[doc(hidden)]
+pub trait IsMinusOne {
+    fn is_minus_one(&self) -> bool;
+}
+
+macro_rules! impl_is_minus_one {
+    ($($t:ident)*) => ($(impl IsMinusOne for $t {
+        fn is_minus_one(&self) -> bool {
+            *self == -1
+        }
+    })*)
+}
+
+impl_is_minus_one! { i8 i16 i32 i64 isize }
+
+pub fn cvt<T: IsMinusOne>(t: T) -> io::Result<T> {
+    if t.is_minus_one() {
+        Err(io::Error::last_os_error())
+    } else {
+        Ok(t)
+    }
+}
+
+pub fn cvt_r<T, F>(mut f: F) -> io::Result<T>
+    where T: IsMinusOne,
+          F: FnMut() -> T
+{
+    loop {
+        match cvt(f()) {
+            Err(ref e) if e.kind() == ErrorKind::Interrupted => {}
+            other => return other,
+        }
+    }
+}
+
 pub unsafe fn abort_internal() -> ! {
     ::libc::abort()
 }

ctr-std/src/sys/unix/time.rs

@@ -0,0 +1,270 @@
+// Copyright 2015 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+use cmp::Ordering;
+use libc;
+use time::Duration;
+
+pub use self::inner::{Instant, SystemTime, UNIX_EPOCH};
+
+const NSEC_PER_SEC: u64 = 1_000_000_000;
+
+#[derive(Copy, Clone)]
+struct Timespec {
+    t: libc::timespec,
+}
+
+impl Timespec {
+    fn sub_timespec(&self, other: &Timespec) -> Result<Duration, Duration> {
+        if self >= other {
+            Ok(if self.t.tv_nsec >= other.t.tv_nsec {
+                Duration::new((self.t.tv_sec - other.t.tv_sec) as u64,
+                              (self.t.tv_nsec - other.t.tv_nsec) as u32)
+            } else {
+                Duration::new((self.t.tv_sec - 1 - other.t.tv_sec) as u64,
+                              self.t.tv_nsec as u32 + (NSEC_PER_SEC as u32) -
+                              other.t.tv_nsec as u32)
+            })
+        } else {
+            match other.sub_timespec(self) {
+                Ok(d) => Err(d),
+                Err(d) => Ok(d),
+            }
+        }
+    }
+
+    fn add_duration(&self, other: &Duration) -> Timespec {
+        let secs = (self.t.tv_sec as i64).checked_add(other.as_secs() as i64);
+        let mut secs = secs.expect("overflow when adding duration to time");
+
+        // Nano calculations can't overflow because nanos are <1B which fit
+        // in a u32.
+        let mut nsec = other.subsec_nanos() + self.t.tv_nsec as u32;
+        if nsec >= NSEC_PER_SEC as u32 {
+            nsec -= NSEC_PER_SEC as u32;
+            secs = secs.checked_add(1).expect("overflow when adding \
+                                               duration to time");
+        }
+        Timespec {
+            t: libc::timespec {
+                tv_sec: secs as libc::time_t,
+                tv_nsec: nsec as libc::c_long,
+            },
+        }
+    }
+
+    fn sub_duration(&self, other: &Duration) -> Timespec {
+        let secs = (self.t.tv_sec as i64).checked_sub(other.as_secs() as i64);
+        let mut secs = secs.expect("overflow when subtracting duration \
+                                    from time");
+
+        // Similar to above, nanos can't overflow.
+        let mut nsec = self.t.tv_nsec as i32 - other.subsec_nanos() as i32;
+        if nsec < 0 {
+            nsec += NSEC_PER_SEC as i32;
+            secs = secs.checked_sub(1).expect("overflow when subtracting \
+                                               duration from time");
+        }
+        Timespec {
+            t: libc::timespec {
+                tv_sec: secs as libc::time_t,
+                tv_nsec: nsec as libc::c_long,
+            },
+        }
+    }
+}
+
+impl PartialEq for Timespec {
+    fn eq(&self, other: &Timespec) -> bool {
+        self.t.tv_sec == other.t.tv_sec && self.t.tv_nsec == other.t.tv_nsec
+    }
+}
+
+impl Eq for Timespec {}
+
+impl PartialOrd for Timespec {
+    fn partial_cmp(&self, other: &Timespec) -> Option<Ordering> {
+        Some(self.cmp(other))
+    }
+}
+
+impl Ord for Timespec {
+    fn cmp(&self, other: &Timespec) -> Ordering {
+        let me = (self.t.tv_sec, self.t.tv_nsec);
+        let other = (other.t.tv_sec, other.t.tv_nsec);
+        me.cmp(&other)
+    }
+}
+
+mod inner {
+    use fmt;
+    use libc;
+    use sys::cvt;
+    use sys_common::mul_div_u64;
+    use time::Duration;
+
+    use super::NSEC_PER_SEC;
+    use super::Timespec;
+
+    use spin;
+    use libctru;
+
+    #[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Debug)]
+    pub struct Instant {
+        t: u64
+    }
+
+    #[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord)]
+    pub struct SystemTime {
+        t: Timespec,
+    }
+
+    pub const UNIX_EPOCH: SystemTime = SystemTime {
+        t: Timespec {
+            t: libc::timespec {
+                tv_sec: 0,
+                tv_nsec: 0,
+            },
+        },
+    };
+
+    impl Instant {
+        pub fn now() -> Instant {
+            Instant { t: ctr_absolute_time() }
+        }
+
+        pub fn sub_instant(&self, other: &Instant) -> Duration {
+            let info = info();
+            let diff = self.t.checked_sub(other.t)
+                           .expect("second instant is later than self");
+            let nanos = mul_div_u64(diff, info.numer as u64, info.denom as u64);
+            Duration::new(nanos / NSEC_PER_SEC, (nanos % NSEC_PER_SEC) as u32)
+        }
+
+        pub fn add_duration(&self, other: &Duration) -> Instant {
+            Instant {
+                t: self.t.checked_add(dur2intervals(other))
+                       .expect("overflow when adding duration to instant"),
+            }
+        }
+
+        pub fn sub_duration(&self, other: &Duration) -> Instant {
+            Instant {
+                t: self.t.checked_sub(dur2intervals(other))
+                       .expect("overflow when adding duration to instant"),
+            }
+        }
+    }
+
+    // The initial system tick after which all Instants occur
+    static TICK: spin::Once<u64> = spin::Once::new();
+
+    // A source of monotonic time based on ticks of the 3DS CPU. Returns the
+    // number of system ticks elapsed since an arbitrary point in the past
+    fn ctr_absolute_time() -> u64 {
+        let first_tick = get_first_tick();
+        let current_tick = get_system_tick();
+        current_tick - first_tick
+    }
+
+    // The first time this function is called, it generates and returns the
+    // initial system tick used to create Instants
+    //
+    // subsequent calls to this function return the previously generated
+    // tick value
+    fn get_first_tick() -> u64 {
+        *TICK.call_once(get_system_tick)
+    }
+
+    // Gets the current system tick
+    #[inline]
+    fn get_system_tick() -> u64 {
+        unsafe { libctru::svc::svcGetSystemTick() }
+    }
+
+    // A struct representing the clock speed of the 3DS
+    struct CtrClockInfo {
+        numer: u32,
+        denom: u32,
+    }
+
+    // Initializes the CtrClockInfo struct
+    //
+    // Note that svcGetSystemTick always runs at 268MHz (268,111,856Hz), even
+    // on a New 3DS running in 804MHz mode
+    //
+    // See https://www.3dbrew.org/wiki/Hardware#Common_hardware
+    fn info() -> CtrClockInfo {
+        CtrClockInfo {
+            numer: 1_000_000_000,
+            denom: 268_111_856,
+        }
+    }
+
+    fn dur2intervals(dur: &Duration) -> u64 {
+        let info = info();
+        let nanos = dur.as_secs().checked_mul(NSEC_PER_SEC).and_then(|nanos| {
+            nanos.checked_add(dur.subsec_nanos() as u64)
+        }).expect("overflow converting duration to nanoseconds");
+        mul_div_u64(nanos, info.denom as u64, info.numer as u64)
+    }
+
+    impl SystemTime {
+        pub fn now() -> SystemTime {
+            use ptr;
+
+            let mut s = libc::timeval {
+                tv_sec: 0,
+                tv_usec: 0,
+            };
+            cvt(unsafe {
+                libc::gettimeofday(&mut s, ptr::null_mut())
+            }).unwrap();
+            return SystemTime::from(s)
+        }
+
+        pub fn sub_time(&self, other: &SystemTime)
+                        -> Result<Duration, Duration> {
+            self.t.sub_timespec(&other.t)
+        }
+
+        pub fn add_duration(&self, other: &Duration) -> SystemTime {
+            SystemTime { t: self.t.add_duration(other) }
+        }
+
+        pub fn sub_duration(&self, other: &Duration) -> SystemTime {
+            SystemTime { t: self.t.sub_duration(other) }
+        }
+    }
+
+    impl From<libc::timeval> for SystemTime {
+        fn from(t: libc::timeval) -> SystemTime {
+            SystemTime::from(libc::timespec {
+                tv_sec: t.tv_sec,
+                tv_nsec: (t.tv_usec * 1000) as libc::c_long,
+            })
+        }
+    }
+
+    impl From<libc::timespec> for SystemTime {
+        fn from(t: libc::timespec) -> SystemTime {
+            SystemTime { t: Timespec { t: t } }
+        }
+    }
+
+    impl fmt::Debug for SystemTime {
+        fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+            f.debug_struct("SystemTime")
+             .field("tv_sec", &self.t.t.tv_sec)
+             .field("tv_nsec", &self.t.t.tv_nsec)
+             .finish()
+        }
+    }
+}

ctr-std/src/time/duration.rs

@@ -0,0 +1,420 @@
+// Copyright 2012-2014 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+use ops::{Add, Sub, Mul, Div, AddAssign, SubAssign, MulAssign, DivAssign};
+
+const NANOS_PER_SEC: u32 = 1_000_000_000;
+const NANOS_PER_MILLI: u32 = 1_000_000;
+const MILLIS_PER_SEC: u64 = 1_000;
+
+/// A duration type to represent a span of time, typically used for system
+/// timeouts.
+///
+/// Each duration is composed of a number of seconds and nanosecond precision.
+/// APIs binding a system timeout will typically round up the nanosecond
+/// precision if the underlying system does not support that level of precision.
+///
+/// Durations implement many common traits, including `Add`, `Sub`, and other
+/// ops traits. Currently a duration may only be inspected for its number of
+/// seconds and its nanosecond precision.
+///
+/// # Examples
+///
+/// ```
+/// use std::time::Duration;
+///
+/// let five_seconds = Duration::new(5, 0);
+/// let five_seconds_and_five_nanos = five_seconds + Duration::new(0, 5);
+///
+/// assert_eq!(five_seconds_and_five_nanos.as_secs(), 5);
+/// assert_eq!(five_seconds_and_five_nanos.subsec_nanos(), 5);
+///
+/// let ten_millis = Duration::from_millis(10);
+/// ```
+#[stable(feature = "duration", since = "1.3.0")]
+#[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Debug, Hash, Default)]
+pub struct Duration {
+    secs: u64,
+    nanos: u32, // Always 0 <= nanos < NANOS_PER_SEC
+}
+
+impl Duration {
+    /// Creates a new `Duration` from the specified number of seconds and
+    /// additional nanosecond precision.
+    ///
+    /// If the nanoseconds is greater than 1 billion (the number of nanoseconds
+    /// in a second), then it will carry over into the seconds provided.
+    ///
+    /// # Panics
+    ///
+    /// This constructor will panic if the carry from the nanoseconds overflows
+    /// the seconds counter.
+    #[stable(feature = "duration", since = "1.3.0")]
+    #[inline]
+    pub fn new(secs: u64, nanos: u32) -> Duration {
+        let secs = secs.checked_add((nanos / NANOS_PER_SEC) as u64)
+            .expect("overflow in Duration::new");
+        let nanos = nanos % NANOS_PER_SEC;
+        Duration { secs: secs, nanos: nanos }
+    }
+
+    /// Creates a new `Duration` from the specified number of seconds.
+    #[stable(feature = "duration", since = "1.3.0")]
+    #[inline]
+    pub fn from_secs(secs: u64) -> Duration {
+        Duration { secs: secs, nanos: 0 }
+    }
+
+    /// Creates a new `Duration` from the specified number of milliseconds.
+    #[stable(feature = "duration", since = "1.3.0")]
+    #[inline]
+    pub fn from_millis(millis: u64) -> Duration {
+        let secs = millis / MILLIS_PER_SEC;
+        let nanos = ((millis % MILLIS_PER_SEC) as u32) * NANOS_PER_MILLI;
+        Duration { secs: secs, nanos: nanos }
+    }
+
+    /// Returns the number of whole seconds represented by this duration.
+    ///
+    /// The extra precision represented by this duration is ignored (i.e. extra
+    /// nanoseconds are not represented in the returned value).
+    #[stable(feature = "duration", since = "1.3.0")]
+    #[inline]
+    pub fn as_secs(&self) -> u64 { self.secs }
+
+    /// Returns the nanosecond precision represented by this duration.
+    ///
+    /// This method does **not** return the length of the duration when
+    /// represented by nanoseconds. The returned number always represents a
+    /// fractional portion of a second (i.e. it is less than one billion).
+    #[stable(feature = "duration", since = "1.3.0")]
+    #[inline]
+    pub fn subsec_nanos(&self) -> u32 { self.nanos }
+
+    /// Checked duration addition. Computes `self + other`, returning `None`
+    /// if overflow occurred.
+    ///
+    /// # Examples
+    ///
+    /// Basic usage:
+    ///
+    /// ```
+    /// #![feature(duration_checked_ops)]
+    ///
+    /// use std::time::Duration;
+    ///
+    /// assert_eq!(Duration::new(0, 0).checked_add(Duration::new(0, 1)), Some(Duration::new(0, 1)));
+    /// assert_eq!(Duration::new(1, 0).checked_add(Duration::new(std::u64::MAX, 0)), None);
+    /// ```
+    #[unstable(feature = "duration_checked_ops", issue = "35774")]
+    #[inline]
+    pub fn checked_add(self, rhs: Duration) -> Option<Duration> {
+        if let Some(mut secs) = self.secs.checked_add(rhs.secs) {
+            let mut nanos = self.nanos + rhs.nanos;
+            if nanos >= NANOS_PER_SEC {
+                nanos -= NANOS_PER_SEC;
+                if let Some(new_secs) = secs.checked_add(1) {
+                    secs = new_secs;
+                } else {
+                    return None;
+                }
+            }
+            debug_assert!(nanos < NANOS_PER_SEC);
+            Some(Duration {
+                secs: secs,
+                nanos: nanos,
+            })
+        } else {
+            None
+        }
+    }
+
+    /// Checked duration subtraction. Computes `self + other`, returning `None`
+    /// if the result would be negative or if underflow occurred.
+    ///
+    /// # Examples
+    ///
+    /// Basic usage:
+    ///
+    /// ```
+    /// #![feature(duration_checked_ops)]
+    ///
+    /// use std::time::Duration;
+    ///
+    /// assert_eq!(Duration::new(0, 1).checked_sub(Duration::new(0, 0)), Some(Duration::new(0, 1)));
+    /// assert_eq!(Duration::new(0, 0).checked_sub(Duration::new(0, 1)), None);
+    /// ```
+    #[unstable(feature = "duration_checked_ops", issue = "35774")]
+    #[inline]
+    pub fn checked_sub(self, rhs: Duration) -> Option<Duration> {
+        if let Some(mut secs) = self.secs.checked_sub(rhs.secs) {
+            let nanos = if self.nanos >= rhs.nanos {
+                self.nanos - rhs.nanos
+            } else {
+                if let Some(sub_secs) = secs.checked_sub(1) {
+                    secs = sub_secs;
+                    self.nanos + NANOS_PER_SEC - rhs.nanos
+                } else {
+                    return None;
+                }
+            };
+            debug_assert!(nanos < NANOS_PER_SEC);
+            Some(Duration { secs: secs, nanos: nanos })
+        } else {
+            None
+        }
+    }
+
+    /// Checked duration multiplication. Computes `self * other`, returning
+    /// `None` if underflow or overflow occurred.
+    ///
+    /// # Examples
+    ///
+    /// Basic usage:
+    ///
+    /// ```
+    /// #![feature(duration_checked_ops)]
+    ///
+    /// use std::time::Duration;
+    ///
+    /// assert_eq!(Duration::new(0, 500_000_001).checked_mul(2), Some(Duration::new(1, 2)));
+    /// assert_eq!(Duration::new(std::u64::MAX - 1, 0).checked_mul(2), None);
+    /// ```
+    #[unstable(feature = "duration_checked_ops", issue = "35774")]
+    #[inline]
+    pub fn checked_mul(self, rhs: u32) -> Option<Duration> {
+        // Multiply nanoseconds as u64, because it cannot overflow that way.
+        let total_nanos = self.nanos as u64 * rhs as u64;
+        let extra_secs = total_nanos / (NANOS_PER_SEC as u64);
+        let nanos = (total_nanos % (NANOS_PER_SEC as u64)) as u32;
+        if let Some(secs) = self.secs
+            .checked_mul(rhs as u64)
+            .and_then(|s| s.checked_add(extra_secs)) {
+            debug_assert!(nanos < NANOS_PER_SEC);
+            Some(Duration {
+                secs: secs,
+                nanos: nanos,
+            })
+        } else {
+            None
+        }
+    }
+
+    /// Checked duration division. Computes `self / other`, returning `None`
+    /// if `other == 0` or the operation results in underflow or overflow.
+    ///
+    /// # Examples
+    ///
+    /// Basic usage:
+    ///
+    /// ```
+    /// #![feature(duration_checked_ops)]
+    ///
+    /// use std::time::Duration;
+    ///
+    /// assert_eq!(Duration::new(2, 0).checked_div(2), Some(Duration::new(1, 0)));
+    /// assert_eq!(Duration::new(1, 0).checked_div(2), Some(Duration::new(0, 500_000_000)));
+    /// assert_eq!(Duration::new(2, 0).checked_div(0), None);
+    /// ```
+    #[unstable(feature = "duration_checked_ops", issue = "35774")]
+    #[inline]
+    pub fn checked_div(self, rhs: u32) -> Option<Duration> {
+        if rhs != 0 {
+            let secs = self.secs / (rhs as u64);
+            let carry = self.secs - secs * (rhs as u64);
+            let extra_nanos = carry * (NANOS_PER_SEC as u64) / (rhs as u64);
+            let nanos = self.nanos / rhs + (extra_nanos as u32);
+            debug_assert!(nanos < NANOS_PER_SEC);
+            Some(Duration { secs: secs, nanos: nanos })
+        } else {
+            None
+        }
+    }
+}
+
+#[stable(feature = "duration", since = "1.3.0")]
+impl Add for Duration {
+    type Output = Duration;
+
+    fn add(self, rhs: Duration) -> Duration {
+        self.checked_add(rhs).expect("overflow when adding durations")
+    }
+}
+
+#[stable(feature = "time_augmented_assignment", since = "1.9.0")]
+impl AddAssign for Duration {
+    fn add_assign(&mut self, rhs: Duration) {
+        *self = *self + rhs;
+    }
+}
+
+#[stable(feature = "duration", since = "1.3.0")]
+impl Sub for Duration {
+    type Output = Duration;
+
+    fn sub(self, rhs: Duration) -> Duration {
+        self.checked_sub(rhs).expect("overflow when subtracting durations")
+    }
+}
+
+#[stable(feature = "time_augmented_assignment", since = "1.9.0")]
+impl SubAssign for Duration {
+    fn sub_assign(&mut self, rhs: Duration) {
+        *self = *self - rhs;
+    }
+}
+
+#[stable(feature = "duration", since = "1.3.0")]
+impl Mul<u32> for Duration {
+    type Output = Duration;
+
+    fn mul(self, rhs: u32) -> Duration {
+        self.checked_mul(rhs).expect("overflow when multiplying duration by scalar")
+    }
+}
+
+#[stable(feature = "time_augmented_assignment", since = "1.9.0")]
+impl MulAssign<u32> for Duration {
+    fn mul_assign(&mut self, rhs: u32) {
+        *self = *self * rhs;
+    }
+}
+
+#[stable(feature = "duration", since = "1.3.0")]
+impl Div<u32> for Duration {
+    type Output = Duration;
+
+    fn div(self, rhs: u32) -> Duration {
+        self.checked_div(rhs).expect("divide by zero error when dividing duration by scalar")
+    }
+}
+
+#[stable(feature = "time_augmented_assignment", since = "1.9.0")]
+impl DivAssign<u32> for Duration {
+    fn div_assign(&mut self, rhs: u32) {
+        *self = *self / rhs;
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::Duration;
+
+    #[test]
+    fn creation() {
+        assert!(Duration::from_secs(1) != Duration::from_secs(0));
+        assert_eq!(Duration::from_secs(1) + Duration::from_secs(2),
+                   Duration::from_secs(3));
+        assert_eq!(Duration::from_millis(10) + Duration::from_secs(4),
+                   Duration::new(4, 10 * 1_000_000));
+        assert_eq!(Duration::from_millis(4000), Duration::new(4, 0));
+    }
+
+    #[test]
+    fn secs() {
+        assert_eq!(Duration::new(0, 0).as_secs(), 0);
+        assert_eq!(Duration::from_secs(1).as_secs(), 1);
+        assert_eq!(Duration::from_millis(999).as_secs(), 0);
+        assert_eq!(Duration::from_millis(1001).as_secs(), 1);
+    }
+
+    #[test]
+    fn nanos() {
+        assert_eq!(Duration::new(0, 0).subsec_nanos(), 0);
+        assert_eq!(Duration::new(0, 5).subsec_nanos(), 5);
+        assert_eq!(Duration::new(0, 1_000_000_001).subsec_nanos(), 1);
+        assert_eq!(Duration::from_secs(1).subsec_nanos(), 0);
+        assert_eq!(Duration::from_millis(999).subsec_nanos(), 999 * 1_000_000);
+        assert_eq!(Duration::from_millis(1001).subsec_nanos(), 1 * 1_000_000);
+    }
+
+    #[test]
+    fn add() {
+        assert_eq!(Duration::new(0, 0) + Duration::new(0, 1),
+                   Duration::new(0, 1));
+        assert_eq!(Duration::new(0, 500_000_000) + Duration::new(0, 500_000_001),
+                   Duration::new(1, 1));
+    }
+
+    #[test]
+    fn checked_add() {
+        assert_eq!(Duration::new(0, 0).checked_add(Duration::new(0, 1)),
+                   Some(Duration::new(0, 1)));
+        assert_eq!(Duration::new(0, 500_000_000).checked_add(Duration::new(0, 500_000_001)),
+                   Some(Duration::new(1, 1)));
+        assert_eq!(Duration::new(1, 0).checked_add(Duration::new(::u64::MAX, 0)), None);
+    }
+
+    #[test]
+    fn sub() {
+        assert_eq!(Duration::new(0, 1) - Duration::new(0, 0),
+                   Duration::new(0, 1));
+        assert_eq!(Duration::new(0, 500_000_001) - Duration::new(0, 500_000_000),
+                   Duration::new(0, 1));
+        assert_eq!(Duration::new(1, 0) - Duration::new(0, 1),
+                   Duration::new(0, 999_999_999));
+    }
+
+    #[test]
+    fn checked_sub() {
+        let zero = Duration::new(0, 0);
+        let one_nano = Duration::new(0, 1);
+        let one_sec = Duration::new(1, 0);
+        assert_eq!(one_nano.checked_sub(zero), Some(Duration::new(0, 1)));
+        assert_eq!(one_sec.checked_sub(one_nano),
+                   Some(Duration::new(0, 999_999_999)));
+        assert_eq!(zero.checked_sub(one_nano), None);
+        assert_eq!(zero.checked_sub(one_sec), None);
+    }
+
+    #[test] #[should_panic]
+    fn sub_bad1() {
+        Duration::new(0, 0) - Duration::new(0, 1);
+    }
+
+    #[test] #[should_panic]
+    fn sub_bad2() {
+        Duration::new(0, 0) - Duration::new(1, 0);
+    }
+
+    #[test]
+    fn mul() {
+        assert_eq!(Duration::new(0, 1) * 2, Duration::new(0, 2));
+        assert_eq!(Duration::new(1, 1) * 3, Duration::new(3, 3));
+        assert_eq!(Duration::new(0, 500_000_001) * 4, Duration::new(2, 4));
+        assert_eq!(Duration::new(0, 500_000_001) * 4000,
+                   Duration::new(2000, 4000));
+    }
+
+    #[test]
+    fn checked_mul() {
+        assert_eq!(Duration::new(0, 1).checked_mul(2), Some(Duration::new(0, 2)));
+        assert_eq!(Duration::new(1, 1).checked_mul(3), Some(Duration::new(3, 3)));
+        assert_eq!(Duration::new(0, 500_000_001).checked_mul(4), Some(Duration::new(2, 4)));
+        assert_eq!(Duration::new(0, 500_000_001).checked_mul(4000),
+                   Some(Duration::new(2000, 4000)));
+        assert_eq!(Duration::new(::u64::MAX - 1, 0).checked_mul(2), None);
+    }
+
+    #[test]
+    fn div() {
+        assert_eq!(Duration::new(0, 1) / 2, Duration::new(0, 0));
+        assert_eq!(Duration::new(1, 1) / 3, Duration::new(0, 333_333_333));
+        assert_eq!(Duration::new(99, 999_999_000) / 100,
+                   Duration::new(0, 999_999_990));
+    }
+
+    #[test]
+    fn checked_div() {
+        assert_eq!(Duration::new(2, 0).checked_div(2), Some(Duration::new(1, 0)));
+        assert_eq!(Duration::new(1, 0).checked_div(2), Some(Duration::new(0, 500_000_000)));
+        assert_eq!(Duration::new(2, 0).checked_div(0), None);
+    }
+}

ctr-std/src/time/mod.rs

@@ -0,0 +1,447 @@
+// Copyright 2012-2014 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+//! Temporal quantification.
+//!
+//! Example:
+//!
+//! ```
+//! use std::time::Duration;
+//!
+//! let five_seconds = Duration::new(5, 0);
+//! // both declarations are equivalent
+//! assert_eq!(Duration::new(5, 0), Duration::from_secs(5));
+//! ```
+
+#![stable(feature = "time", since = "1.3.0")]
+
+use error::Error;
+use fmt;
+use ops::{Add, Sub, AddAssign, SubAssign};
+use sys::time;
+use sys_common::FromInner;
+
+#[stable(feature = "time", since = "1.3.0")]
+pub use self::duration::Duration;
+
+mod duration;
+
+/// A measurement of a monotonically increasing clock.
+///  Opaque and useful only with `Duration`.
+///
+/// Instants are always guaranteed to be greater than any previously measured
+/// instant when created, and are often useful for tasks such as measuring
+/// benchmarks or timing how long an operation takes.
+///
+/// Note, however, that instants are not guaranteed to be **steady**.  In other
+/// words, each tick of the underlying clock may not be the same length (e.g.
+/// some seconds may be longer than others). An instant may jump forwards or
+/// experience time dilation (slow down or speed up), but it will never go
+/// backwards.
+///
+/// Instants are opaque types that can only be compared to one another. There is
+/// no method to get "the number of seconds" from an instant. Instead, it only
+/// allows measuring the duration between two instants (or comparing two
+/// instants).
+///
+/// Example:
+///
+/// ```no_run
+/// use std::time::{Duration, Instant};
+/// use std::thread::sleep;
+///
+/// fn main() {
+///    let now = Instant::now();
+///
+///    // we sleep for 2 seconds
+///    sleep(Duration::new(2, 0));
+///    // it prints '2'
+///    println!("{}", now.elapsed().as_secs());
+/// }
+/// ```
+#[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord)]
+#[stable(feature = "time2", since = "1.8.0")]
+pub struct Instant(time::Instant);
+
+/// A measurement of the system clock, useful for talking to
+/// external entities like the file system or other processes.
+///
+/// Distinct from the `Instant` type, this time measurement **is not
+/// monotonic**. This means that you can save a file to the file system, then
+/// save another file to the file system, **and the second file has a
+/// `SystemTime` measurement earlier than the first**. In other words, an
+/// operation that happens after another operation in real time may have an
+/// earlier `SystemTime`!
+///
+/// Consequently, comparing two `SystemTime` instances to learn about the
+/// duration between them returns a `Result` instead of an infallible `Duration`
+/// to indicate that this sort of time drift may happen and needs to be handled.
+///
+/// Although a `SystemTime` cannot be directly inspected, the `UNIX_EPOCH`
+/// constant is provided in this module as an anchor in time to learn
+/// information about a `SystemTime`. By calculating the duration from this
+/// fixed point in time, a `SystemTime` can be converted to a human-readable time,
+/// or perhaps some other string representation.
+///
+/// Example:
+///
+/// ```no_run
+/// use std::time::{Duration, SystemTime};
+/// use std::thread::sleep;
+///
+/// fn main() {
+///    let now = SystemTime::now();
+///
+///    // we sleep for 2 seconds
+///    sleep(Duration::new(2, 0));
+///    match now.elapsed() {
+///        Ok(elapsed) => {
+///            // it prints '2'
+///            println!("{}", elapsed.as_secs());
+///        }
+///        Err(e) => {
+///            // an error occured!
+///            println!("Error: {:?}", e);
+///        }
+///    }
+/// }
+/// ```
+#[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord)]
+#[stable(feature = "time2", since = "1.8.0")]
+pub struct SystemTime(time::SystemTime);
+
+/// An error returned from the `duration_since` method on `SystemTime`,
+/// used to learn how far in the opposite direction a system time lies.
+#[derive(Clone, Debug)]
+#[stable(feature = "time2", since = "1.8.0")]
+pub struct SystemTimeError(Duration);
+
+impl Instant {
+    /// Returns an instant corresponding to "now".
+    #[stable(feature = "time2", since = "1.8.0")]
+    pub fn now() -> Instant {
+        Instant(time::Instant::now())
+    }
+
+    /// Returns the amount of time elapsed from another instant to this one.
+    ///
+    /// # Panics
+    ///
+    /// This function will panic if `earlier` is later than `self`, which should
+    /// only be possible if `earlier` was created after `self`. Because
+    /// `Instant` is monotonic, the only time that this should happen should be
+    /// a bug.
+    #[stable(feature = "time2", since = "1.8.0")]
+    pub fn duration_since(&self, earlier: Instant) -> Duration {
+        self.0.sub_instant(&earlier.0)
+    }
+
+    /// Returns the amount of time elapsed since this instant was created.
+    ///
+    /// # Panics
+    ///
+    /// This function may panic if the current time is earlier than this
+    /// instant, which is something that can happen if an `Instant` is
+    /// produced synthetically.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::thread::sleep;
+    /// use std::time::{Duration, Instant};
+    ///
+    /// let instant = Instant::now();
+    /// let three_secs = Duration::from_secs(3);
+    /// sleep(three_secs);
+    /// assert!(instant.elapsed() >= three_secs);
+    /// ```
+    #[stable(feature = "time2", since = "1.8.0")]
+    pub fn elapsed(&self) -> Duration {
+        Instant::now() - *self
+    }
+}
+
+#[stable(feature = "time2", since = "1.8.0")]
+impl Add<Duration> for Instant {
+    type Output = Instant;
+
+    fn add(self, other: Duration) -> Instant {
+        Instant(self.0.add_duration(&other))
+    }
+}
+
+#[stable(feature = "time_augmented_assignment", since = "1.9.0")]
+impl AddAssign<Duration> for Instant {
+    fn add_assign(&mut self, other: Duration) {
+        *self = *self + other;
+    }
+}
+
+#[stable(feature = "time2", since = "1.8.0")]
+impl Sub<Duration> for Instant {
+    type Output = Instant;
+
+    fn sub(self, other: Duration) -> Instant {
+        Instant(self.0.sub_duration(&other))
+    }
+}
+
+#[stable(feature = "time_augmented_assignment", since = "1.9.0")]
+impl SubAssign<Duration> for Instant {
+    fn sub_assign(&mut self, other: Duration) {
+        *self = *self - other;
+    }
+}
+
+#[stable(feature = "time2", since = "1.8.0")]
+impl Sub<Instant> for Instant {
+    type Output = Duration;
+
+    fn sub(self, other: Instant) -> Duration {
+        self.duration_since(other)
+    }
+}
+
+#[stable(feature = "time2", since = "1.8.0")]
+impl fmt::Debug for Instant {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        self.0.fmt(f)
+    }
+}
+
+impl SystemTime {
+    /// Returns the system time corresponding to "now".
+    #[stable(feature = "time2", since = "1.8.0")]
+    pub fn now() -> SystemTime {
+        SystemTime(time::SystemTime::now())
+    }
+
+    /// Returns the amount of time elapsed from an earlier point in time.
+    ///
+    /// This function may fail because measurements taken earlier are not
+    /// guaranteed to always be before later measurements (due to anomalies such
+    /// as the system clock being adjusted either forwards or backwards).
+    ///
+    /// If successful, `Ok(Duration)` is returned where the duration represents
+    /// the amount of time elapsed from the specified measurement to this one.
+    ///
+    /// Returns an `Err` if `earlier` is later than `self`, and the error
+    /// contains how far from `self` the time is.
+    #[stable(feature = "time2", since = "1.8.0")]
+    pub fn duration_since(&self, earlier: SystemTime)
+                          -> Result<Duration, SystemTimeError> {
+        self.0.sub_time(&earlier.0).map_err(SystemTimeError)
+    }
+
+    /// Returns the amount of time elapsed since this system time was created.
+    ///
+    /// This function may fail as the underlying system clock is susceptible to
+    /// drift and updates (e.g. the system clock could go backwards), so this
+    /// function may not always succeed. If successful, `Ok(duration)` is
+    /// returned where the duration represents the amount of time elapsed from
+    /// this time measurement to the current time.
+    ///
+    /// Returns an `Err` if `self` is later than the current system time, and
+    /// the error contains how far from the current system time `self` is.
+    #[stable(feature = "time2", since = "1.8.0")]
+    pub fn elapsed(&self) -> Result<Duration, SystemTimeError> {
+        SystemTime::now().duration_since(*self)
+    }
+}
+
+#[stable(feature = "time2", since = "1.8.0")]
+impl Add<Duration> for SystemTime {
+    type Output = SystemTime;
+
+    fn add(self, dur: Duration) -> SystemTime {
+        SystemTime(self.0.add_duration(&dur))
+    }
+}
+
+#[stable(feature = "time_augmented_assignment", since = "1.9.0")]
+impl AddAssign<Duration> for SystemTime {
+    fn add_assign(&mut self, other: Duration) {
+        *self = *self + other;
+    }
+}
+
+#[stable(feature = "time2", since = "1.8.0")]
+impl Sub<Duration> for SystemTime {
+    type Output = SystemTime;
+
+    fn sub(self, dur: Duration) -> SystemTime {
+        SystemTime(self.0.sub_duration(&dur))
+    }
+}
+
+#[stable(feature = "time_augmented_assignment", since = "1.9.0")]
+impl SubAssign<Duration> for SystemTime {
+    fn sub_assign(&mut self, other: Duration) {
+        *self = *self - other;
+    }
+}
+
+#[stable(feature = "time2", since = "1.8.0")]
+impl fmt::Debug for SystemTime {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        self.0.fmt(f)
+    }
+}
+
+/// An anchor in time which can be used to create new `SystemTime` instances or
+/// learn about where in time a `SystemTime` lies.
+///
+/// This constant is defined to be "1970-01-01 00:00:00 UTC" on all systems with
+/// respect to the system clock. Using `duration_since` on an existing
+/// `SystemTime` instance can tell how far away from this point in time a
+/// measurement lies, and using `UNIX_EPOCH + duration` can be used to create a
+/// `SystemTime` instance to represent another fixed point in time.
+#[stable(feature = "time2", since = "1.8.0")]
+pub const UNIX_EPOCH: SystemTime = SystemTime(time::UNIX_EPOCH);
+
+impl SystemTimeError {
+    /// Returns the positive duration which represents how far forward the
+    /// second system time was from the first.
+    ///
+    /// A `SystemTimeError` is returned from the `duration_since`
+    /// operation whenever the second system time represents a point later
+    /// in time than the `self` of the method call.
+    #[stable(feature = "time2", since = "1.8.0")]
+    pub fn duration(&self) -> Duration {
+        self.0
+    }
+}
+
+#[stable(feature = "time2", since = "1.8.0")]
+impl Error for SystemTimeError {
+    fn description(&self) -> &str { "other time was not earlier than self" }
+}
+
+#[stable(feature = "time2", since = "1.8.0")]
+impl fmt::Display for SystemTimeError {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "second time provided was later than self")
+    }
+}
+
+impl FromInner<time::SystemTime> for SystemTime {
+    fn from_inner(time: time::SystemTime) -> SystemTime {
+        SystemTime(time)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::{Instant, SystemTime, Duration, UNIX_EPOCH};
+
+    macro_rules! assert_almost_eq {
+        ($a:expr, $b:expr) => ({
+            let (a, b) = ($a, $b);
+            if a != b {
+                let (a, b) = if a > b {(a, b)} else {(b, a)};
+                assert!(a - Duration::new(0, 100) <= b);
+            }
+        })
+    }
+
+    #[test]
+    fn instant_monotonic() {
+        let a = Instant::now();
+        let b = Instant::now();
+        assert!(b >= a);
+    }
+
+    #[test]
+    fn instant_elapsed() {
+        let a = Instant::now();
+        a.elapsed();
+    }
+
+    #[test]
+    fn instant_math() {
+        let a = Instant::now();
+        let b = Instant::now();
+        let dur = b.duration_since(a);
+        assert_almost_eq!(b - dur, a);
+        assert_almost_eq!(a + dur, b);
+
+        let second = Duration::new(1, 0);
+        assert_almost_eq!(a - second + second, a);
+    }
+
+    #[test]
+    #[should_panic]
+    fn instant_duration_panic() {
+        let a = Instant::now();
+        (a - Duration::new(1, 0)).duration_since(a);
+    }
+
+    #[test]
+    fn system_time_math() {
+        let a = SystemTime::now();
+        let b = SystemTime::now();
+        match b.duration_since(a) {
+            Ok(dur) if dur == Duration::new(0, 0) => {
+                assert_almost_eq!(a, b);
+            }
+            Ok(dur) => {
+                assert!(b > a);
+                assert_almost_eq!(b - dur, a);
+                assert_almost_eq!(a + dur, b);
+            }
+            Err(dur) => {
+                let dur = dur.duration();
+                assert!(a > b);
+                assert_almost_eq!(b + dur, a);
+                assert_almost_eq!(b - dur, a);
+            }
+        }
+
+        let second = Duration::new(1, 0);
+        assert_almost_eq!(a.duration_since(a - second).unwrap(), second);
+        assert_almost_eq!(a.duration_since(a + second).unwrap_err()
+                           .duration(), second);
+
+        assert_almost_eq!(a - second + second, a);
+
+        let eighty_years = second * 60 * 60 * 24 * 365 * 80;
+        assert_almost_eq!(a - eighty_years + eighty_years, a);
+        assert_almost_eq!(a - (eighty_years * 10) + (eighty_years * 10), a);
+
+        let one_second_from_epoch = UNIX_EPOCH + Duration::new(1, 0);
+        let one_second_from_epoch2 = UNIX_EPOCH + Duration::new(0, 500_000_000)
+            + Duration::new(0, 500_000_000);
+        assert_eq!(one_second_from_epoch, one_second_from_epoch2);
+    }
+
+    #[test]
+    fn system_time_elapsed() {
+        let a = SystemTime::now();
+        drop(a.elapsed());
+    }
+
+    #[test]
+    fn since_epoch() {
+        let ts = SystemTime::now();
+        let a = ts.duration_since(UNIX_EPOCH).unwrap();
+        let b = ts.duration_since(UNIX_EPOCH - Duration::new(1, 0)).unwrap();
+        assert!(b > a);
+        assert_eq!(b - a, Duration::new(1, 0));
+
+        // let's assume that we're all running computers later than 2000
+        let thirty_years = Duration::new(1, 0) * 60 * 60 * 24 * 365 * 30;
+        assert!(a > thirty_years);
+
+        // let's assume that we're all running computers earlier than 2090.
+        // Should give us ~70 years to fix this!
+        let hundred_twenty_years = thirty_years * 4;
+        assert!(a < hundred_twenty_years);
+    }
+}